#include <stdio.h>

int main() {
    int a, b,d;
    while(scanf("%d %d %d",&a,&b,&d)!=EOF)
    {
      if(a+b>d&&a-b<d)
    {
        
        if(a==b&&b==d)
        {printf("Equilateral triangle!\n");}

        
         else if(a==b||b==d||a==d)
        {printf("Isosceles triangle!");printf("\n");} 
        
        else
        {printf("Ordinary triangle!");
         printf("\n");}
    }
    else 
    {
       printf("Not a triangle!");
       printf("\n");
    }
   
    } 
  
    return 0;
}
